Avatar Type Affects Performance of Cognitive Tasks in Virtual Reality

Current consumer virtual reality applications typically represent the user by an avatar comprising a simple head/torso and decoupled hands. In the prior work of Steed et al. it was shown that the presence or absence of an avatar could have a significant impact on the cognitive load of the user. We extend that work in two ways. First they only used a full-body avatar with articulated arms, so we add a condition with hands-only representation similar to the majority of current consumer applications. Second we provide a real-world benchmark so as to start to get at the impact of using any immersive system. We validate the prior results: real and full body avatar performance on a memory task is significantly better than no avatar. However the hands only condition is not significantly different than either these two extremes. We discuss why this might be, in particular we discuss the potential for a individual variation in response to the embodiment level

Material Visualisation for Virtual Reality: The Perceptual Investigations

Material representation plays a significant role in design visualisation and evaluation. On one hand, the simulated material properties determine the appearance of product prototypes in digitally rendered scenes. On the other hand, those properties are perceived by the viewers in order to make important design decisions. As an approach to simulate a more realistic environment, Virtual Reality (VR) provides users a vivid impression of depth and embodies them into an immersive environment. However, the scientific understanding of material perception and its applications in VR is still fairly limited. This leads to this thesis’s research question on whether the material perception in VR is different from that in traditional 2D displays, as well as the potential of using VR as a design tool to facilitate material evaluation.       This thesis is initiated from studying the perceptual difference of rendered materials between VR and traditional 2D viewing modes. Firstly, through a pilot study, it is confirmed that users have different perceptual experiences of the same material in the two viewing modes. Following that initial finding, the research investigates in more details the perceptual difference with psychophysics methods, which help in quantifying the users’ perceptual responses. Using the perceptual scale as a measuring means, the research analyses the users’ judgment and recognition of the material properties under VR and traditional 2D display environments. In addition, the research also elicits the perceptual evaluation criteria to analyse the emotional aspects of materials. The six perceptual criteria are in semantic forms, including rigidity, formality, fineness, softness, modernity, and irregularity.       The results showed that VR could support users in making a more refined judgment of material properties. That is to say, the users perceive better the minute changes of material properties under immersive viewing conditions. In terms of emotional aspects, VR is advantageous in signifying the effects induced by visual textures, while the 2D viewing mode is more effective for expressing the characteristics of plain surfaces. This thesis has contributed to the deeper understanding of users’ perception of material appearances in Virtual Reality, which is critical in achieving an effective design visualisation using such a display medium